A typical vehicle headlight assembly includes a reflector and a lamp placed with its light source at or near the focal point of the reflector. Currently, the majority of such lamps are of halogen type while some high end automobiles use High Intensity Discharge (HID) lamps and, in recent years, not only HID lamps, but also light-emitting diode (LED) retrofit bulbs have also been introduced to such assembly. The reflector commonly includes a poly-ellipsoid rear portion and flat wall sections between the rear portion and the front of the assembly. The front is usually covered with a transparent lens. Typically, the lens, the reflector, or a combination of both is designed to direct the light from the light source into a specified pattern.
Several prior art methods have been used to control the light emitted from the lamp in vehicle headlight assemblies. One common method is to mount a shuttle in front of the bulb, to make the bulb having a dual function—a high beam and a low beam function through setting down or raising the shuttle. However, such a method of controlling the light emitted by the lamp results in inefficiencies in the headlight assembly, particularly for the low beam function, because they prevent a large percentage of the light emitted by the lamp from being used by the headlight assembly for example through absorption by the raised shuttle.